Clips are devices shaped like a steel strip of metal designed to load ammunition into a firearm or magazine. You won’t see firearm clips unless the gun you’re loading is an antique (think WWI or WWII).
Magazines are what we traditionally think of when we’re talking about modern weapons. A magazine isn’t a strip, it’s more of a box. Inside is a spring with a plastic or metal follower at the top. Rounds are loaded into the magazine, compressing the spring. The spring tension is what pushes the rounds to the top so your firearm can load them into the chamber.